1. Field of the Invention
The present invention relates to a bearing sealing device and a bearing sealing mechanism for outer ring rotating type bearings such as bearings for axles, and bearings for engine accessories like outer ring rotating type water pumps, idlers and tensioners.
2. Description of the Prior Art
Conventionally, as a bearing sealing device of this type, there is one as shown in FIG. 9. The sealing device includes a main lip 73 that is put in slidable contact with a side surface 72A located axially outwardly of an annular groove 72 formed on an outer peripheral surface 71A of an inner ring 71, and an auxiliary lip 75 provided with interposition of a specified clearance to a slant side surface 72B arranged opposite to the side surface 72A. The main lip 73 and the auxiliary lip 75 are converged at their roots to be integrated into one body, and a radially outward end portion (not shown) thereof is fixed to an outer ring (not shown).
In the sealing device, the auxiliary lip 75 intercepts grease from inside the bearing. Further, the grease that has passed around the auxiliary lip 75 is intercepted by the main lip 73.
However, in the above prior art bearing sealing device, a pressure force exerted from the main lip 73 on the side surface 72A is sometimes weakened by a centrifugal force depending on use conditions, and therefore the grease that has passed around the auxiliary lip 75 possibly passes around the main lip 73. The above also results in the problem that the leak of the grease is incompletely prevented.